Pierre-Louis de Maupertuis studied the polydactylic hands of a single German family in which the trait had been passed for generations.

1698-1759 Pierre-Louis Moreau de MaupertuisIn his 1751 book, Système de la nature (System of Nature), French mathematician, biologist, and astronomer Pierre-Louis Moreau de Maupertuis initiated the first speculations into the modern idea of dominant and recessive genes. De Maupertuis studied the occurrences of polydactyly (extra fingers) among several generations of one family and showed how this trait could be passed through both its male and female members. He even surmised that polydactyly was the result of a mutation in the "hereditary particles" of an individual and devised a mathematical means of predicting the occurrence of the trait in the family's future offspring.